In general, blood perfusion entails forcing blood through the vessels of a bodily organ. For such purposes, blood perfusion systems typically entail the use of one or more pumps in an extracorporeal circuit that is interconnected with the vascular system of a patient.
Of particular interest, cardiopulmonary bypass surgery requires a perfusion system that provides for the temporary cessation of the heart to create a still operating field by replacing the function of the heart and lungs. Such isolation allows for the surgical correction of vascular stenosis, valvular disorders, and congenital heart defects. In perfusion systems used for cardiopulmonary bypass surgery, an extracorporeal blood circuit is established that includes at least one pump and an oxygenation device to replace the functions of the heart and lungs.
More specifically, in cardiopulmonary bypass procedures oxygen-poor blood, i.e., venous blood, is gravity-drained or suctioned from a large vein entering the heart or other veins in the body (e.g., femoral) and is transferred through a venous line in the extracorporeal circuit. The venous blood is pumped to an oxygenator that provides for oxygen transfer to the blood. Oxygen may be introduced into the blood by transfer across a membrane or, less frequently, by bubbling oxygen through the blood. Concurrently, CO2 is removed across the membrane. The oxygenated blood is then returned through an arterial line to the aorta, femoral, or other artery.
In addition to the above-noted components, extracorporeal fluid circuits used for cardiopulmonary bypass procedures also typically provide for the flow of a cardioplegia mixture through a cardioplegia line into the root of the aorta, coronaries and/or coronary sinus in order to nourish, arrest, and maintain the arrest of the heart. The cardioplegia mixture is typically circulated through a heat exchanger prior to patient delivery. Additional devices that can be employed include a reservoir to hold the venous blood, a heat exchanger to cool or heat the returned blood, and various filters to keep particles greater than a predetermined size from passage into the patient.
Further, extracorporeal fluid circuits utilized during cardiopulmonary bypass procedures may also include various suction lines. Such lines are employed to remove blood that collects in the thoracic cavity during surgery. Such blood may contain debris such as skin, air, bone chips, etc. and may be salvaged via filtering and routed to a reservoir for subsequent washing and/or oxygenation and return to the patient. A vent line may also be utilized to remove blood that accumulates in the heart or vasculature (e.g., aortic root, pulmonary artery, etc.) during the bypass procedure. Removal of such accumulated blood may be important to avoid heart distention. The vented blood may be routed to a reservoir for subsequent oxygenation and return to the patient or washing. In addition to the above-noted components, extracorporeal fluid circuits utilized in connection with cardiopulmonary bypass procedures may include components for the introduction into the blood of various nutrients and pharmaceuticals.
The various fluid circuitry and components of an extracorporeal circuit are set up by medical personnel prior to the bypass procedure. This can be a time consuming process since many of the connections are made by hand. As will be appreciated, this set-up procedure is also the source of potential error. Any incorrect or leaky connection can jeopardize both the success of the surgical procedure and the safety of the patient. Further, such an approach has entailed the separate setup and monitoring of each circuit by medical personnel during the course of a cardiopulmonary bypass procedure. Further, establishment of the operative interrelationships between the various circuits has been left to the attention and coordination of medical personnel. In view of the foregoing it would be desirable to have an integrated perfusion system which is easy to set-up, use and monitor during the bypass procedure. Such a system should eliminate many of the sources of error in the set-up, monitoring and use of conventional extracorporeal perfusion circuits as well as improve system monitoring and safety. The present invention comprises an integrated perfusion system which overcomes many of the disadvantages of present perfusion systems.